A5076114412- Arctic and Antarctic ice dynamics
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Climate change and permafrost
- Oceanographic and Atmospheric Processes
- Geological Studies and Exploration
- Atmospheric and Environmental Gas Dynamics
- Underwater Acoustics Research
- Marine and coastal ecosystems
- Geology and Paleoclimatology Research
- Climate variability and models
- Ocean Acidification Effects and Responses
- Underwater Vehicles and Communication Systems
- Hydrology and Watershed Management Studies
- Hydrocarbon exploration and reservoir analysis
- Geophysics and Gravity Measurements
- Water Quality and Resources Studies
- Arctic and Russian Policy Studies
- Marine Biology and Ecology Research
- Geological formations and processes
- Distributed and Parallel Computing Systems
- Target Tracking and Data Fusion in Sensor Networks
- Coastal and Marine Management
- Marine and environmental studies
- Icing and De-icing Technologies
Woods Hole Oceanographic Institution
2015-2024
Oceanography Society
2011-2017
University of Montana
2016
Fisheries and Oceans Canada
2011
Pacific Biosciences (United States)
2011
University of Cape Town
2011
Tokyo University of Marine Science and Technology
2011
Federal Maritime and Hydrographic Agency of Germany
1990
Cold Regions Research and Engineering Laboratory
1990
Universität Hamburg
1990
Satellite records show a decline in ice extent over more than three decades, with record minimum September 2012. Results from the Pan‐Arctic Ice‐Ocean Modelling and Assimilation system (PIOMAS) suggest that has been accompanied by volume, but this not confirmed data. Using new data European Space Agency CryoSat‐2 (CS‐2) mission, validated situ data, we generate estimates of volume for winters 2010/11 2011/12. We compare these current PIOMAS earlier (2003–8) National Aeronautics...
Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening the halocline, shoaling intermediate-depth Atlantic Water layer eastern Eurasian Basin have increased winter ventilation ocean interior, making this region structurally similar western Basin. The associated enhanced release oceanic heat has reduced formation at rate now comparable losses from thermodynamic forcing, thus...
Particle fluxes measured with time series sediment traps deployed below 2000 m at 68 sites in the world ocean are combined satellite‐derived estimates of export production from overlying water to assess factors affecting transfer particulate organic matter surface deep water. Multiple linear regression is used derive an algorithm suggesting that efficiency carbon, defined as settling flux carbon normalized production, increases carbonate and decreases depth seasonality. The predicts >80%...
We investigate basin‐scale mechanisms regulating anomalies in freshwater content (FWC) the Beaufort Gyre (BG) of Arctic Ocean using historical observations and data collected 2003–2007. Specifically, mean annual cycle interannual decadal FWC variability are explored. The major cause large BG is process Ekman pumping (EP) due to High anticyclonic circulation centered BG. seasonal liquid a result interplay between mechanical thermal (ice transformations) factors has two peaks. One peak occurs...
Author Posting. © Oceanography Society, 2011. This article is posted here by permission of Society for personal use, not redistribution. The definitive version was published in 24 no. 3 (2011): 126–135, doi:10.5670/oceanog.2011.64.
Abstract Time series of ice draft from 2003 to 2012 moored sonar data are used investigate variability and describe the reduction perennial sea cover in Beaufort Gyre (BG), culminating extreme minimum 2012. Negative trends median drafts most fractions observed, while open water thinnest (<0.3 m) have increased, attesting ablation or removal older BG over 9 year period. Monthly anomalies indicate a shift occurred toward thinner after 2007, which thicker evident at northern stations was...
Abstract Hydrographic data collected from research cruises, bottom‐anchored moorings, drifting Ice‐Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of Arctic Ocean document an increase more than 6,400 km 3 liquid freshwater content 2003 to 2018: a 40% growth relative climatology 1970s. This fresh water accumulation is shown result persistent anticyclonic atmospheric wind forcing (1997–2018) accompanied by sea ice melt, wind‐forced redirection Mackenzie River discharge...
Freshwater in the Arctic Ocean plays an important role regional ocean circulation, sea ice, and global climate. From salinity observed by a variety of platforms, we are able, for first time, to estimate statistically reliable liquid freshwater trend from monthly gridded fields over all upper basins. 1992 2012 this was 600±300 km 3 yr −1 . A numerical model agrees very well with changes. decrease made up about two thirds thickening layer one third. The Oscillation index, measure wind stress...
Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic anticyclonic alternating at 5 to 7 year intervals. During regimes, low sea-level atmospheric pressure (SLP) dominated over Ocean driving sea ice upper ocean counterclockwise; atmosphere was relatively warm humid, freshwater flux from towards subarctic seas intensified. By contrast, during anticylonic high SLP clockwise....
Arctic Ocean properties and processes are highly relevant to the regional global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part Multidisciplinary drifting Observatory for Study Climate (MOSAiC), drift with sea ice from October 2019 September 2020. An international team designed implemented program characterize system unprecedented detail, seafloor air-sea ice-ocean interface,...
Variations in the Arctic central Canada Basin mixed layer properties are documented based on a subset of nearly 6500 temperature and salinity profiles acquired by Ice‐Tethered Profilers during period summer 2004 to 2009 analyzed conjunction with sea ice observations from mass balance buoys atmosphere‐ocean heat flux estimates. The July–August mean depth Profiler data averaged 16 m (an overestimate due sampling characteristics present analysis procedures), while average winter was only 24 m,...
Abstract An automated, easily deployed Ice-Tethered Profiler (ITP) instrument system, developed for deployment on perennial sea ice in the polar oceans to measure changes upper ocean water properties all seasons, is described, and representative data from prototype instruments are presented. The ITP consists of three components: a surface subsystem that sits atop an floe; weighted, plastic-jacketed wire-rope tether arbitrary length (up 800 m) suspended element; instrumented underwater unit...
Six Ice‐Tethered Profilers (ITP), deployed in the central Canada Basin of Arctic Ocean between 2004 and 2007, have provided detailed potential temperature salinity measurements a double‐diffusive staircase at about 200–300 m depth. Individual layers are order 1 vertical height but appear to extend horizontally for hundreds kilometers, with along‐layer gradients tightly related. On basis laboratory‐derived flux laws, estimated heat fluxes through range 0.05–0.3 W −2 , only one tenth mean...
Pacific Water flows northward through Bering Strait and penetrates the Arctic Ocean halocline throughout Canadian Basin sector of Arctic.In summer, Summer (PSW) is modified by surface buoyancy fluxes mixing as it crosses shallow Chukchi Sea before entering deep ocean.Measurements from Ice-Tethered Profilers, moorings, hydrographic surveys between 2003 2013 reveal spatial temporal variability in PSW component Central Canada with increasing trends integrated heat freshwater content, a...
Reduced sea ice cover opens a conduit for solar-heated water to reach the interior Arctic Basin halocline.
Abstract Ice‐Tethered Profilers (ITP), deployed in the Arctic Ocean between 2004 and 2013, have provided detailed temperature salinity measurements of an assortment halocline eddies. A total 127 mesoscale eddies been detected, 95% which were anticyclones, majority had anomalously cold cores. These cold‐core anticyclonic observed Beaufort Gyre region (Canadian water eddies) vicinity Transpolar Drift Stream (Eurasian eddies). An Arctic‐wide calculation first baroclinic Rossby deformation...
[1] Data collected by an autonomous ice-based observatory that drifted into the Eurasian Basin between April and November 2010 indicate upper ocean was appreciably fresher than in 2007 2008. Sea ice snowmelt over course of drift amounted to input less 0.5 m liquid freshwater (comparable freshening melting estimated for those previous years), while observed change upper-ocean salinity melt period implies a gain about 0.7 m. Results wind-driven model corroborate observations suggest unusually...
Central Arctic properties and processes are important to the regional global coupled climate system. The Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) Distributed Network (DN) autonomous ice-tethered systems aimed bridge gaps in our understanding temporal spatial scales, particular with respect resolution Earth system models. By characterizing variability around local measurements made at a Observatory, DN covers both interactions involving ocean-ice-atmosphere...
Abstract The ice–ocean system is investigated on inertial to monthly time scales using winter 2009–10 observations from the first ice-tethered profiler (ITP) equipped with a velocity sensor (ITP-V). Fluctuations in surface winds, ice velocity, and ocean at 7-m depth were correlated. Observed was primarily directed right of spiraled clockwise while decaying through mixed layer. Inertial tidal motions underlying observed throughout record. Just below interface, direct estimates turbulent...
Abstract The eddy field across the Arctic Ocean's Canada Basin is analyzed using Ice‐Tethered Profiler (ITP) and moored measurements of temperature, salinity, velocity spanning 2005 to 2015. ITPs encountered 243 eddies, 98% which were anticyclones, with approximately 70% these having anomalously cold cores. spatially temporally varying accounting for sampling biases in unevenly distributed ITP data caveats detection methods. highest concentration eddies was found western southern portions...
A model-observation synthesis is conducted to investigate changes in the upper ocean circulation and stratification Canada Basin [CB] of Arctic Ocean. Results show that Beaufort Gyre [BG] has been generally intensifying during 1992–2015 conjunction with sea ice including increasing surface height [SSH], speed, Ekman transport convergence downwelling, freshwater content, decreasing thickness salinity, shoaling summer halocline mixed layer, deepening winter layer. Increasing draws more water...